Donor neutralization in GaAs(Si) by atomic hydrogen

Abstract

Hydrogen plasma exposure of n-type GaAs(Si) at 250 °C results in a decrease of the free-carrier concentration by several orders of magnitude. This neutralization effect has been demonstrated in silicon-doped layers grown by molecular beam epitaxy or formed by annealed implants as well as in bulk material. The same effect is produced electrochemically (H3PO4 electrolyte), whereas helium plasma exposure has no effect, thus confirming the role of hydrogen insertion. The hydrogen penetration depth into GaAs(Si) is inversely dependent on the Si concentration. Recovery of the electrical activity follows first order dissociation kinetics with a dissociation energy of 2.1 eV. Complete restoration of free-carrier concentration occurs by heating at 420 °C for less than 3 min. Extrapolated to low temperatures, these results imply many years of stability at 150 °C or below.

Wafer Mapping Using Deuterium Enhanced Defect Characterization

“…As such, hydrogen can also interact strongly with chemical impurities within the lattice. 10,11 Initial evaluation of deuterium tagging of defects in epitaxial MCT films grown by molecular-beam epitaxy on a 19% lattice-mismatched Si(211) substrate was done using secondary-ion mass spectrometry (SIMS) to determine the deuterium profiles. SIMS profiles are shown in Fig.…”

Electron-induced dissociation of SiH complexes in hydrogenated Si-doped GaAs. Application to the fabrication of microstructures

“…In such devices, hot electron degradation due to the breaking of SiH bonds and to the formation of dangling bonds is observed and recently, it has been shown [1] that the reduction of this degradation and the improvement of the device lifetime could be achieved by incorporating deuterium rather than hydrogen. For Si-doped GaAs materials and devices, the ability of hydrogen to passivate the electrically active shallow impurities and as a consequence to form an electrically neutral SiH complex is well known [2]. So, it is of interest to study the influence of hot electrons on the stability of complexes and the related isotope effects.…”

Hydrogen Passivation in Semiconductors

“…Chevallier et al [58] demonstrated donor passivation in GaAs before it was known that donors could be passivated in Si. Subsequently, all of the important donor dopants in GaAs have been shown to be passivated by H2 plasma exposure [59].…”